Click the above figure to expand

Click the above figure to expand

Excited-state analysis : A powerful algorithm has been produced
for attacking highly tangled potential surfaces in the excited states!

Automated analysis of minimum on seam of crossing (MSX) :
Automated serch of the mysterious world of excited-state potentials becomes possible!

In the excited-satates various potential surfaces are intermingled to cross each other.
Chemical reactions in the excited-states proceed through seams of crossing (Left figure above).
Finding such seams of crossing is very difficult, because the position and the shape crucially
depend on the quality of the electronic-state calculations. Moreover, prediction of such seams
based on experience or inspiration is almost impossible.
GRRM program enables us to search Minimum on Seam of Crossing (MAX) systematically and automatically.

Automated analysis of conical intersections on potential surfaces

When symmetries of two excited-states are the same for both spin and space, two potentials give Conical Intersection (CI)
as shown in the above figure (a). When symmetries are different, a seam of crossing appears as shown in the above left figure.
CI has a very difficult problem arising from the crossing point, which is mathematically singular.
In the GRRM program, this corssing point is replaced by a smooth function (avoiding model function).
With this technique, reaction route mapping can be performed even in the excited-states as the case of the ground state by
the GRRM program. This is an advantage of GRRM to explore excited-state potential surfaces; it is especially valuable for
photochemical analyses.